RTO 20
Vishay Sfernice
Power Resistors Thick Film Technology
FEATURES
•
•
•
•
•
•
20 W at 25 °C Heatsink Mounted
High Power Dissipation to size ratio
Wide Resistance Range from 0.01
Ω
to 1 MΩ
Negligible Inductance
Easy Mounting
TO 220 package: Compact and easy to mount
RoHS
COMPLIANT
The well known TO 220 package is compact and easy to
mount.
Two versions of this thick film resistor are available:
•
A Radial Leaded version for PCB Mounting
•
A Flat Lead version for Surface Mounting
DIMENSIONS
in millimeters
RTO 20F - LEADED
4.5
10.1
RTO 20C - FOR SURFACE MOUNTING
4.5
Ø 3.6
1.3
10.1
Ø 3.6
1.3
12.5
15
8.8
12.5
15
8.8
13.7
2
3
1.6
0.3
5.08
Ø 0.8
5.08
• Tolerance unless otherwise specified: ± 0.4 mm
2.5
• Only for RTO 20 version C = during surface mount soldering temperature profile
must not cause the metal tab of this device to exceed 220 °C.
MECHANICAL SPECIFICATIONS
Mechanical Protection
Resistive Element
Connections
Weight
Insulated Case
Thick Film
Tinned copper
2.2 g max.
ELECTRICAL SPECIFICATIONS
Resistance Range
Tolerances (Standard)
Dissipation and
Associated:
Thermal Resistance
and Nominal Power
0.010
Ω
to 1 MΩ serie E24
± 1 % to ± 10 %
Onto a heatsink
20 W at + 25 °C
R
TH
(j-c): 6.5 °C/W
free air:
2 W at + 25 °C
See Performance table
± 150 ppm/°C
250 V
2000 V
RMS
- 1 min - 10 mA Max
(Between Terminals and Heatsink)
≥
10
6
MΩ
≤
0.1 µH
3.12 kΩ
DIMENSIONS
Standard Package
TO 220
Insulated case
Temperature Coefficient
Standard
(- 55 °C; + 150 °C)
Limiting Element Voltage
Dielectric Strength
MIL STD 202
Insulation Resistance
Inductance
Critical Resistance
ENVIRONMENTAL SPECIFICATIONS
Temperature Range
Climatic Category
Sealing
Flammability
- 55 °C to + 155 °C
55/155/56
Sealed container
Solder immersion
IEC 60695-11-5
2 applications 30 s seperated
by 60 s
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For technical questions, contact: sfer@vishay.com
Document Number: 50005
Revision: 05-Jun-07
RTO 20
Power Resistors Thick Film Technology
Vishay Sfernice
PERFORMANCE
TESTS
CONDITIONS
EN 60115-1
2 Pr for R < 2
Ω
1.6 Pr for R
≥
2
Ω
Us < 1.5 UL
EN 60115-1/60068-2-14
5 cycles
- 55 °C to + 155 °C
EN 60115-1
1000 h Pr at + 25 °C
EN 60115-1
56 days R.H. 95 %
NF EN 140 000
1000 h - 40 % Pr at + 100 °C
MIL STD 202, Method 204 C Test D
MIL STD 202, Method 211 Test A1
IEC 60115-1
IEC 60068-2-27
Saw tooth: 100 g/6 ms
TYPICAL DRIFTS
Momentary Overload
± (0.25 % + 0.005
Ω)
Rapid Temperature Change
± (0.5 % + 0.005
Ω)
Load Life
Humidity (Steady State)
High Temperature Exposure
Vibration
Terminal Strength
Shock
± (1 % + 0.005
Ω)
± (0.5 % + 0.005
Ω)
± (0.5 % + 0.005
Ω)
± (0.2 % + 0.005
Ω)
± (0.2 % + 0.005
Ω)
± (0.5 % + 0.005
Ω)
SPECIAL FEATURES
Resistance Values
Tolerances
Typical Temperature
Coefficient Range
(- 55 °C/+ 155 °C)
± 900 ppm/°C
≥
0.01
≥
0.015
± 1 % at ± 10 %
± 700 ppm/°C
± 250 ppm/°C
± 150 ppm/°C
≥
0.1
≥
0.5
Note:
For very low ohmic values, TCR for information
CHOICE OF THE HEATSINK
The user must choose according to the working conditions of the component (power, room temperature).
Maximum working temperature must not exceed 155 °C. The dissipated power is simply calculated by the following ratio:
(
1
)
ΔT
-
P = ------------------------------------------------------------
[
R
TH
(j-c) + R
TH
(c-a)
]
P:
ΔT:
R
TH
:
R
TH
:
Example:
expressed in W
difference between maximum working temperature and room temperature
(j-c): thermal resistance value measured between resistive layer and outer side of the resistor. It is the thermal
resistance of the component: (Special Features Table)
(c-a): thermal resistance value measured between outer side of the resistor and room temperature. It is the thermal
resistance of the heatsink itself (type, shape) and the quality of the fastening device.
R
TH
: (c-a) for RTO 20 power rating 10 W at ambient temperature + 25 °C
Thermal resistance R
TH
(j-c): 6.5 °C/W
Considering equation (1) we have:
ΔT
=
155 °C - 25 °C
=
130 °C
ΔT
130
-
-
R
TH
(j-c) + R
TH
(c-a) = ------ = --------- = 13 °C/W
P
10
R
TH
(c-a) = 13 °C/W - 6.5 °C/W = 6.5 °C/W
Document Number: 50005
Revision: 05-Jun-07
For technical questions, contact: sfer@vishay.com
www.vishay.com
15
RTO 20
Vishay Sfernice
OVERLOADS
In any case the applied voltage must be lower than the maximum overload voltage of 375 V.
The values indicated on the graph below are applicable to resistors in air or mounted onto a heatsink.
Power Resistors Thick Film Technology
ENERGY CURVE
100
ENERGY IN JOULES
10
1
0.1
0.01
10
-7
10
-6
10
-5
10
-4
10
-3
10
-2
10
-1
OVERLOAD DURATION IN SECONDS
POWER RATING CHART
The temperature of the heatsink should be maintained within the limits specified.
To improve the thermal conductivity, surfaces in contact should be coated with a silicone grease and the torque applied on the
screw for tightening should be around 1 Nm. Spring clip can also be used to mount the component on an heatsink (ex: Kunze,
clip KU4-498).
120
100
%
RATED POWER
75
50
25
0
0
20
40
60
80
100
120
140
155
HEATSINK TEMPERATURE IN °C
MARKING
Model, Style, Resistance Value (in
Ω),
Tolerance (in %), Manufacturing Date, VISHAY trademark.
PACKAGING
Tube of 50 units
ORDERING INFORMATION
RTO
MODEL
20
STYLE
F
CONNECTIONS
F: Radial Leads
C: Surface Mount
U68
RESISTANCE VALUE
5%
TOLERANCE
±1%
±2%
±5%
± 10 %
xxx
CUSTOM DESIGN
Optional
on request:
special TCR,
shape etc.
TU50
PACKAGING
e3
LEAD (Pb)-FREE
SAP PART NUMBERING GUIDELINES
RTO
MODEL
020
STYLE
F
CONNECTIONS
R6800
RESISTANCE VALUE
J
TOLERANCE
T
PACKAGING
e3
LEAD (Pb)-FREE
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For technical questions, contact: sfer@vishay.com
Document Number: 50005
Revision: 05-Jun-07
Legal Disclaimer Notice
Vishay
Disclaimer
All product specifications and data are subject to change without notice.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf
(collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein
or in any other disclosure relating to any product.
Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any
information provided herein to the maximum extent permitted by law. The product specifications do not expand or
otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed
therein, which apply to these products.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this
document or by any conduct of Vishay.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless
otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such
applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting
from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding
products designed for such applications.
Product names and markings noted herein may be trademarks of their respective owners.
Document Number: 91000
Revision: 18-Jul-08
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1